1. Field of the Invention
The present invention relates to a charger for charging a secondary battery, such as a nickel cadmium battery (a Ni—Cd battery) and a nickel hydride battery (a Ni-MH battery), and, more particularly, to a charger for reducing power consumption in a standby mode in which charging is not performed.
2. Description of the Related Art
High capacity secondary batteries, such as a Ni—Cd battery and a Ni-MH battery, are being widely used as a power supply for portable equipment, such as an electric tool. On the other hand, with increases in the capacity of the secondary battery, increases in the output capacity of a charger for charging such a battery in a short time is proceeding.
A secondary battery charger adapted to reduce power consumption in a standby mode, in which charging is not performed, has been proposed. JP-A-2004-187366 discloses a battery charger adapted so that an output voltage in a standby mode is set to be lower than an output voltage used during charging, thereby to realize low power consumption in a standby mode in which charging is not performed.
However, it is difficult for the related charger to eliminate power consumption in a standby mode. The related charger is insufficient to realize low power consumption in a standby mode.